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Wednesday, August 28, 2013

Helpful SQL Queries

SQL queries are easily readable if they are in a standard SQL format; this can be achieved with the help of an online SQL formatting tool at:http://www.dpriver.com/pp/sqlformat.htm 

1. Following set of queries can be used to get various values from the database.
  • Find all columns in a Database
SELECT SC.name AS ColumnName,
       ST.name AS TableName
FROM   sys.columns SC
       INNER JOIN sys.tables ST
               ON ST.object_id = SC.object_id
ORDER  BY ST.name,
          SC.name 
  • List all the Functions in a Database

SELECT name AS function_name,
       type_desc
FROM   sys.objects
WHERE  type_desc LIKE '%FUNCTION%'; 


  • List all the Stored Procedures in a Database 
SELECT name
FROM   sys.procedures
ORDER  BY name 

  • List all the views in a Database
SELECT name
FROM   sys.views
ORDER  BY name 
  
  • List all the tables in a Database
SELECT name
FROM   sys.tables
  • Find specific column and related table names
SELECT t.name AS table_name,SCHEMA_NAME(schema_idAS schema_name,c.name AS column_name
FROM sys.tables AS 
t
INNER JOIN sys.columns c ON t.OBJECT_ID 
c.OBJECT_ID
WHERE c.name LIKE 
'%column name%'ORDER BY schema_nametable_name
  • Data type of a column

SELECT 
    c.name 'Column Name',
    t.Name 'Data type',
    c.max_length 'Max Length',
    c.precision ,
    c.scale ,
    c.is_nullable,
    ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM    
    sys.columns c
INNER JOIN 
    sys.types t ON c.system_type_id = t.system_type_id
LEFT OUTER JOIN 
    sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN 
    sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE 
    c.object_id = OBJECT_ID('YourTableName')
  • Find specific column and related table names
SELECT t.name AS table_name, SCHEMA_NAME(schema_id) AS schema_name, c.name AS column_name FROM sys.tables AS t INNER JOIN sys.columns c ON t.OBJECT_ID = c.OBJECT_ID WHERE c.name LIKE '%column name%' ORDER BY schema_name, table_name
2. Queries to check if best practice is followed in SPs
SELECT routine_name,
       routine_definition
FROM   information_schema.routines
WHERE  routine_definition LIKE '%select * from%'
       AND routine_type = 'PROCEDURE' 
Note: Verify for each combination, i.e., select*from, select *from, select* from.
  • Query to identify if any SP uses IN or Not IN

SELECT routine_name,
       routine_definition
FROM   information_schema.routines
WHERE  routine_definition LIKE '% in (%'
       AND routine_type = 'PROCEDURE' 
SELECT routine_name,
       routine_definition
FROM   information_schema.routines
WHERE  routine_definition LIKE '% not in (%'
       AND routine_type = 'PROCEDURE' 
Note: Verify for each combination of IN and Not IN, i.e., ‘IN(‘, ‘ IN (‘, ‘NotIN(‘, ‘Not IN(‘, ‘Not IN (‘.
  • SP without initial comment
SELECT ROUTINE_NAME, ROUTINE_DEFINITION
FROM INFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_DEFINITION not LIKE '%================%'
AND ROUTINE_TYPE='PROCEDURE'
3. Following queries can be used to get performace details of the database
  • CPU utilization in seconds
SELECT (total_worker_time * 1.0) / 1000000 AS CPU_Utilized_in_Seconds, text,*
FROM sys.dm_exec_query_stats
CROSS APPLY sys.dm_exec_sql_text(sql_handle)
order by CPU_Utilized_in_Seconds desc

  • To get longest running query, memory used & other details  
SELECT Top 10 SUBSTRING(qt.TEXT, (qs.statement_start_offset/2)+1,
((CASE qs.statement_end_offset
WHEN -THEN DATALENGTH(qt.TEXT)
ELSE qs.statement_end_offset
END - qs.statement_start_offset)/2)+1),
qs.execution_count,
qs.total_logical_reads, qs.last_logical_reads,
qs.total_logical_writes, qs.last_logical_writes,
qs.total_worker_time,
qs.last_worker_time,
qs.total_elapsed_time/1000000 total_elapsed_time_in_S,
qs.last_elapsed_time/1000000 last_elapsed_time_in_S,
qs.last_execution_time,qp.query_plan
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) qt
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp
ORDER BY qs.total_logical_reads DESC

  • Last query ran on SQL
SELECT deqs.last_execution_time AS [Time]dest.TEXT AS [Query]
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handleAS dest
ORDER BY deqs.last_execution_time DESC
  • Plan cache hit ratio
WITH cte1
     AS (SELECT [dopc].[object_name],
                [dopc].[instance_name],
                [dopc].[counter_name],
                [dopc].[cntr_value],
                [dopc].[cntr_type],
                Row_number()
                  OVER (
                    partition BY [dopc].[object_name], [dopc].[instance_name]
                    ORDER BY [dopc].[counter_name] ) AS r_n
         FROM   [sys].[dm_os_performance_counters] AS dopc
         WHERE  [dopc].[counter_name] LIKE '%Cache Hit Ratio%'
                AND ( [dopc].[object_name] LIKE '%Plan Cache%'
                       OR [dopc].[object_name] LIKE '%Buffer Cache%' )
                AND [dopc].[instance_name] LIKE '%_Total%')
SELECT CONVERT(DECIMAL(16, 2), ( [c].[cntr_value] * 1.0 / [c1].[cntr_value] ) *
                               100.0)
       AS [hit_pct]
FROM   [cte1] AS c
       INNER JOIN [cte1] AS c1
               ON c.[object_name] = c1.[object_name]
                  AND c.[instance_name] = c1.[instance_name]
WHERE  [c].[r_n] = 1
       AND [c1].[r_n] = 2;
  • Plan cache reuse
DECLARE @single DECIMAL(18, 2)
DECLARE @reused DECIMAL(18, 2)
DECLARE @total DECIMAL(18, 2)

SELECT @single = Sum(CASE ( usecounts )
                       WHEN 1 THEN 1
                       ELSE 0
                     END) * 1.0,
       @reused = Sum(CASE ( usecounts )
                       WHEN 1 THEN 0
                       ELSE 1
                     END) * 1.0,
       @total = Count(usecounts) * 1.0
FROM   sys.dm_exec_cached_plans;

SELECT ( @single / @total ) * 100.0; 
  • Identify if a column is reaching limit of the datatype
WITH cte_1
     AS (SELECT Object_name(a.object_id) AS table_name,
                a.name AS columnname,
                CONVERT(BIGINT, Isnull(a.last_value, 0)) AS last_value,
                CASE
                  WHEN b.name = 'tinyint' THEN 255
                  WHEN b.name = 'smallint' THEN 32767
                  WHEN b.name = 'int' THEN 2147483647
                  WHEN b.name = 'bigint' THEN 9223372036854775807
                END    AS dt_value
         FROM   sys.identity_columns a
                INNER JOIN sys.types AS b
                        ON a.system_type_id = b.system_type_id),
     cte_2
     AS (SELECT *,
                CONVERT(NUMERIC(18, 2), ( ( CONVERT(FLOAT, last_value) /
                                            CONVERT(FLOAT, dt_value) ) * 100 ))
                AS 'Percent'
         FROM   cte_1)
SELECT *
FROM   cte_2
ORDER  BY 'Percent' DESC;
  • Number of unused indexes
SELECT db_name() as dbname,
       o.name as tablename,
       i.name as indexname,
       i.index_id,
       user_seeks + user_scans + user_lookups as total_reads,
       user_updates as total_writes,
       (SELECT SUM(p.rows)
          FROM sys.partitions p
         WHERE p.index_id = s.index_id
           AND s.object_id = p.object_id) as number_of_rows,
       s.last_user_lookup,
       s.last_user_scan,
       s.last_user_seek
  FROM sys.indexes i
 INNER JOIN sys.objects o
    ON i.object_id = o.object_id
  LEFT OUTER JOIN sys.dm_db_index_usage_stats s
    ON i.index_id = s.index_id
   AND s.object_id = i.object_id
 WHERE OBJECTPROPERTY(o.object_id, 'IsUserTable') = 1
   AND ISNULL(s.database_id, DB_ID()) = DB_ID()
   AND (
        isnull(s.last_user_seek, '19000101') < datediff(month, -1, getdate()) AND
        isnull(s.last_user_scan, '19000101') < datediff(month, -1, getdate()) AND
        isnull(s.last_user_lookup, '19000101') < datediff(month, -1, getdate())
       )
 ORDER BY total_reads DESC; 
  • Tables without clustered indexes defined
WITH CTE_1
AS
(
  SELECT db_name() as dbname,
         o.name as tablename,
         (SELECT SUM(p.rows)
            FROM sys.partitions p
           WHERE p.index_id = i.index_id
             AND i.object_id = p.object_id) as number_of_rows
    FROM sys.indexes i
   INNER JOIN sys.objects o
      ON i.object_id = o.object_id
   WHERE OBJECTPROPERTY(o.object_id, 'IsUserTable') = 1
     AND OBJECTPROPERTY(o.object_id, 'TableHasClustIndex') = 0
)
SELECT *
  FROM CTE_1
 WHERE number_of_rows > 1000;
  • Possible duplicate indexes

WITH  indexcols
        AS (SELECT object_id AS id,
                index_id AS indid,
                name,
                (SELECT CASE keyno
                          WHEN 0 THEN NULL
                          ELSE colid
                        END AS [data()]
                  FROM sys.sysindexkeys AS k
                  WHERE k.id = i.object_id
                    AND k.indid = i.index_id
                  ORDER BY keyno,
                    colid
                FOR
                 XML PATH('')
                ) AS cols,
                (SELECT CASE keyno
                          WHEN 0 THEN colid
                          ELSE NULL
                        END AS [data()]
                  FROM sys.sysindexkeys AS k
                  WHERE k.id = i.object_id
                    AND k.indid = i.index_id
                  ORDER BY colid
                FOR
                 XML PATH('')
                ) AS inc
              FROM sys.indexes AS i
           )
  SELECT DB_NAME() AS 'DBName',
      OBJECT_SCHEMA_NAME(c1.id) + '.'
        + OBJECT_NAME(c1.id) AS 'TableName',
      c1.name + CASE c1.indid
                  WHEN 1 THEN ' (clustered index)'
                  ELSE ' (nonclustered index)'
                END AS 'IndexName',
      c2.name + CASE c2.indid
                  WHEN 1 THEN ' (clustered index)'
                  ELSE ' (nonclustered index)'
                END AS 'ExactDuplicatedIndexName'
    FROM indexcols AS c1
    INNER JOIN indexcols AS c2
    ON
      c1.id = c2.id
      AND c1.indid < c2.indid
      AND c1.cols = c2.cols
      AND c1.inc = c2.inc;
  • Performance related database settings
DECLARE @Result INT;
DECLARE @High INT; -- For settings you feel need to be right
DECLARE @Med INT; -- For settings you want to know about but arent critical
DECLARE @Low INT; -- For settings that you want flagged but are low importance
SELECT @High = 70,
    @Med = 40,
    @Low = 10;
SELECT @Result = SUM(CASE WHEN [d].[compatibility_level] != [d2].[compatibility_level]
                          THEN @Med
                          ELSE 0
                     END
                   + CASE WHEN [d].[collation_name] != [d2].[collation_name]
                          THEN @Med
                          ELSE 0
                     END
                   + CASE WHEN [d].[user_access] != 0
                          THEN @Low
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_auto_close_on] = 1
                          THEN @High
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_auto_shrink_on] = 1
                          THEN @High
                          ELSE 0
                     END
                   + CASE WHEN [d].[state] != 0
                          THEN @Low
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_auto_create_stats_on] != 1
                          THEN @Med
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_auto_update_stats_on] != 1
                          THEN @Med
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_ansi_nulls_on] = 1
                          THEN @High
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_ansi_padding_on] = 1
                          THEN @High
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_ansi_warnings_on] = 1
                          THEN @High
                          ELSE 0
                     END
                   + CASE WHEN [d].[is_arithabort_on] = 1
THEN @High
                          ELSE 0
                     END)
  FROM [sys].[databases] AS d
  CROSS JOIN [sys].[databases] AS d2
  WHERE [d2].[name] = 'master'
    AND ([d].[database_id] = DB_ID()
    AND [d].[state_desc] = 'Online');
  SELECT @Result;

Monday, July 8, 2013

Making your aspx page IE compatible


We found that in some cases our site is showing some weird UI behavior, It was working fin

e when we are opening our site on clients local machine with
http://localhost but when we use the machine name instead of the local host like (http://machinename ) we are getting a broken UI page.
When we observer the page in IE developer tool (F12) we found that IE 10 is not able to understand the type of document and because of this we are getting the UI error.
To fix this problem we have just added a meta tag after title tag in our pages so that browser can detect correct Browser mode and document Mode
<meta http-equiv="X-UA-Compatible" content="IE=100" />